A major problem with a VQ-based image compression scheme is its codebo
ok search complexity, Recently, a predictive residual vector quantizer
(PRVQ) was proposed in [4], This scheme has a very low search complex
ity, and its performance is very close to that of the predictive vecto
r quantizer (PVQ), This letter presents a new VQ scheme called variabl
e-rate PRVQ (VR-PRVQ), which is designed by imposing a constraint on t
he output entropy of the PRVQ, The proposed VR-PRVQ is found to give a
n excellent rate-distortion performance and deafly outperforms the sta
te-of-the-art image compression algorithm developed by the Joint Photo
graphic Experts Group (JPEG).